A novel one-step synthesis of Ce/Mn/Fe mixed metal oxide nanocomposites for oxidative removal of hydrogen sulfide at room temperature.

In this study, CeO/FeO, CeO/MnO, and CeO/MnO/FeO nanocomposites were synthesized by the calcination of molten salt solutions. The microscopic images confirmed polyhedral nanocrystals of 10-20 nm size, clustered to form nanospheres. The elemental mapping confirmed the uniform distribution of transition metal oxides in the CeO matrix. The X-ray diffraction analysis confirmed the phase purity of metal oxides in nanocomposites. The surface area of nanocomposites was in the range of 16-21 m g. X-ray photoelectron spectroscopy confirmed 25-28% of Ce ions in the CeO of nanocomposites. These nanocomposites were tested for the removal of hydrogen sulfide gas at room temperature. The maximum adsorption capacity of 28.3 mg g was recorded for CeO/MnO/FeO with 500 ppm of HS gas and 0.2 L min of flow rate. The adsorption mechanism probed by X-ray photoelectron spectroscopy showed the presence of sulfate as the only species formed from the oxidation of HS, which was further confirmed by ion chromatography. Thus, the study reports room-temperature oxidation of HS over mixed metal composites, which were synthesized by a novel one-step approach.